The present invention relates to apparatus for analysis of water and, more particularly, to microprocessor controlled apparatus for concurrently performing a series of electrochemical analyses on a sample of swimming pool water.
It has long been known that it is desirable to balance the chemicals added to swimming pool water in order to control bacteria and algae while avoiding excessive free chlorine and limiting the amount of deviation of the pH from neutral. If this balancing is not done properly, contaminated pool water may cause infections or appear cloudy, or the pool wall may become slimy. If free chlorine level and pH are not controlled, the eyes and skin may be irritated.
As a result, pool owners frequently conduct tests to determine pH and chlorine content and, based upon the measured values, add estimated amounts of pool water treatment chemicals. However, the tests which are generally conducted by a home pool owner are of limited character and are generally insufficient to effect full control over the desired chemistry of the water.
Generally, desirable analyses of swimming pool water would include determinations of all or most of the following: cyanuric acid content, pH, free chlorine, dissolved solids, and total alkalinity. With this information, and information as to the total water volume of the pool, it is possible to calculate the amount of various chemical additions required to balance the chemistry of the pool water.
In the late 1970's, Applicant's assignee introduced a computer controlled apparatus utilizing various reagents to effect coulometric evaluation of swimming pool water samples. The operation and accuracy of this apparatus have been enhanced over the years, but there has been a desire to make analysis faster, less complex and more accurate. Moreover, its use of reagents and test tubes for testing has required restocking of reagents and washing of test tubes.
It is an object of the present invention to provide a novel microprocessor controlled apparatus and method for automatically analyzing swimming pool water samples by electrochemical techniques.
It is also an object to provide such apparatus which is reliable and long-lived, and which is simple to operate.
Another object is to provide such apparatus and method which will provide an output indicating the amounts of various chemicals to be added to the pool water to balance its chemistry.
A further object is to provide such apparatus which is simple to maintain and which is operable without reagents or other chemical additives.